3 ms·

That might be true, but I wouldn't expect the microarchitectures that achieve this performance to be free (in either the "gratis" or "libre" senses of that word

That might be true, but I wouldn't expect the microarchitectures that achieve this performance to be free (in either the "gratis" or "libre" senses of that word). Designing a superscalar application processor requires an enormous amount of work by engineers who are experts in their field, and that work needs to be compensated somehow. The ISA may be open, but there is no requirement for the microarchitecture implementing the ISA to be, and it's hard to imagine anyone doing the work to produce a performance-competitive chip and then giving it away. Even if there is a "consortium" model where multiple companies benefit from a single design, they would likely set up some sort of licensing arrangement to prevent free-riding by companies that did not contribute to the design.

tipsysquid 6y ago
> I wouldn't expect the microarchitectures that achieve this performance to be free (in either the "gratis" or "libre" senses of that word) I agree with you on this as an eventuality of risc-v. But my casual following of the space leads me to believe that a high-performance open baseline of these architectures will be available and customization/special purpose of these archs will be for purchase. I'm hopeful some of the benefits will be contributed upstream. As long as there is some competition in the architecture space (ARM, x86, risc-v), the more likely builders will share gains upstream to compete against rival platforms. That's my wishful thinking at least.
- alexhutcheson 6y ago
  I think you’re likely underestimating how complex a modern microarchitecture like the A78 or X1 is compared to the RISC-V cores that have been open sourced so far. It’s unclear to me what organizations would have the resources to develop something like the A78 for RISC-V and would also be happy giving it away for free. Note that in the ARM world everyone except Apple and Nvidia have given up on developing their own microarchitectures - they all just license one from ARM and maybe apply some customizations on top.
nickik 6y ago
There are benefits to having an Open ISA even without all cores being open.

tipsysquid 6y ago

> I wouldn't expect the microarchitectures that achieve this performance to be free (in either the "gratis" or "libre" senses of that word) I agree with you on this as an eventuality of risc-v. But my casual following of the space leads me to believe that a high-performance open baseline of these architectures will be available and customization/special purpose of these archs will be for purchase. I'm hopeful some of the benefits will be contributed upstream. As long as there is some competition in the architecture space (ARM, x86, risc-v), the more likely builders will share gains upstream to compete against rival platforms. That's my wishful thinking at least.

alexhutcheson 6y ago
I think you’re likely underestimating how complex a modern microarchitecture like the A78 or X1 is compared to the RISC-V cores that have been open sourced so far. It’s unclear to me what organizations would have the resources to develop something like the A78 for RISC-V and would also be happy giving it away for free. Note that in the ARM world everyone except Apple and Nvidia have given up on developing their own microarchitectures - they all just license one from ARM and maybe apply some customizations on top.

nickik 6y ago

There are benefits to having an Open ISA even without all cores being open.